Self-assembled structures of block copolymers in selective solvents reproduced by lattice Monte Carlo simulation

A lattice Monte Carlo (MC) simulation was applied to the study of block cop olymers in selective solvent or amphiphilic surfactant solution on the segm ent level, hydrodynamic interactions being neglected. The code was found to be very efficient, employing a partial reptation mode as the elementary mo vement of the self-avoiding lattice chains. Typical self-assembled structur es of block copolymers such as micelle, lamellae. hexagonal cylinder and bi continuous networks have been successfully reproduced without any priori sp ecification of structure. Order-disorder and order-order transitions of dib lock copolymers are systematically studied by adjusting the temperature, th e concentration or the block length ratio in a series computer simulations. The structural differences between micelles composed of ABA and BAB triblo ck copolymers are also explicitly revealed by direct visualisation of the u nderlying chain configurations. The simulation results are consistent with the experimental observations in the literature. This simulation approach i s thus a very useful tool in the extensive investigation of self-assembled structures. It has the advantage that both micro-domains and chain configur ations can be studied with only a comparatively modest call on computationa l resources. (C) 2001 Published by Elsevier Science Ltd.